The Red Sox needed a stopper on Wednesday, a pitcher to shut down the visiting Blue Jays and help them break a five-game losing streak.

Instead, Buchholz seemed lost.

Ostensibly healthy, he continued his mystifying struggles, failing to make it out of the fifth inning for the fourth time in nine starts this season. Toronto clubbed his pitches all over — and sometimes out of — Fenway Park, and handed Boston a 6-4 defeat, the sixth in a row for the Red Sox.

"Far too many at-bats where he pitched behind in the count," manager John Farrell said of Buchholz. "Uncharacteristic for what we know of Clay is that mistakes found their way to the middle of the plate. ... Physically there’s no complaints, no issues. We’ve got to make either an adjustment or a correction mechanically."

Buchholz (2-4) fooled no one Wednesday night. Jose Reyes led off the game by ripping a single to right field. The next three batters all were retired, but all three tagged the ball. Poor placement was the only reason they weren’t doubles.

Edwin Encarnacion then led off the second by drilling a 2-0 fastball into the Monster Seats for the first of two Toronto runs in the inning. Adam Lind began the third by crushing a triple into the triangle in center field, which Encarnacion followed by mashing his second home run of the night, giving the Blue Jays a 4-0 lead.

Toronto loaded the bases later in the inning, forcing Buchholz to throw 34 pitches in the frame, but a two-out rocket off the bat of Jose Bautista was right at shortstop Xander Bogaerts for the third out.

After Shane Victorino hit a solo home run in the fourth off Drew Hutchison (3-3) to cut the Red Sox’ deficit to 4-1, the Blue Jays knocked Buchholz from the game by scoring again in the fifth.

The run was unearned — a two-out single by Dioner Navarro to drive in Lind after Encarnacion had reached on an error — but Buchholz still allowed two hits in the inning.

In 4 2/3, Buchholz gave up five runs — four earned — on nine hits, walked two and struck out two. His earned run average climbed to 6.32.

The Blue Jays swung and missed at just two of the 90 pitches thrown by Buchholz.

"As far as stuff goes, I felt like I had the best stuff in this start velocity-wise that I’ve had all year," said Buchholz. "There’s absolutely nothing physically bothering me. It’s tough to go out there and when you miss one pitch it gets hit every time. That’s where I’m at right now. ... I’m frustrated."

Page 2 of 2 - Taken on its own, it was a bad night. But Buchholz came in with a 6.17 ERA.

On April 5, his first start of the season, Buchholz gave up six runs in 4 1/3 innings — on 13 hits — to the Brewers. Just over two weeks later, he couldn’t make it out of the third inning, allowing six runs in 2 1/3 to the Orioles. And earlier this month in a game at Texas, the Rangers battered Buchholz for six runs on 10 hits in 4 1/3 innings.

Last year, when Buchholz was 12-1 with a 1.74 ERA — while missing half the season with a shoulder problem — he gave up four runs once, three runs once, and two or fewer in every other start.

"I think the last two innings were better," said catcher A.J. Pierzynski. "I know he gave up a run the last inning, but we talked and made some adjustments the last couple of innings and he threw the ball better, so hopefully it carries over to his next start."

In another troubling trend, the Red Sox continued to leave men on base. They rank fourth in all of baseball with a .331 on-base percentage, but the lack of clutch hitting has been crippling.

They were 2-for-6 with runners in scoring position — after starting 0-for-4 — but still left 11 men on base.

"At some point I firmly believe it will turn," said Farrell. "We continue to put double-digit runners on base, and they’re left there. I like to think that at some point this is going to start to turn our way."

After Buchholz departed, Chris Capuano got Anthony Gose to ground into a fielder’s choice to end the fifth. In the seventh, however, Gose got his revenge with a two-out single to center to drive in Juan Francisco for a 6-1 Blue Jays lead.

The Red Sox rallied in the eighth, with Mike Carp stroking a double to deep center to drive in Victorino and Bogaerts following with a double high off the Green Monster to bring home Carp and cut the deficit to 6-3.

Brock Holt then singled to drive in Bogaerts, but Grady Sizemore struck out and Dustin Pedroia grounded out to third to end the inning.

The Red Sox then went down quietly in the ninth against Casey Janssen.

A sixth straight loss is in the books. And something seems terribly amiss with a pitcher crucial to the success of the Red Sox’ season.

Eric Avidon can be reached at 508-626-3809 or eavidon@wickedlocal.com. Follow him on Twitter @ericavidon.